Spring starter for internal combustion engines



2,990,827 SPRING STARTER FOR INTERNAL COMBUSTION ENGINES Filed Dec. 8,1958 E. KAWECKI July 4, 1961 5 Sheets-Sheet 1 I .1. LIJ. J. 4

W NR y 4, 1961 E. KAWECKI 2,990,827

SPRING STARTER FOR INTERNAL COMBUSTIQN ENGINES Filed Dec. 8, 1958 3Sheets-Sheet 2 INVENTOR.

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rrai/v /sz Uflitfii S te atw O 2,990,827 SPRING STARTER FOR INTERNALCOMBUSTION ENGINES Eugene Kawecki, Birmingham, Mich., assignor toClinton Engines Corporation, Clinton, Mich., a corporation of Michigan 7Filed Dec. 8, 1958, Ser. No. 778,893 r Claims. (Cl. 123-179)'I'hisinvention relates to a starter for an internal combustion engineand more particularly to a spring powered starter for small internalcombustion engines such as the single cylinder engines commonly employedon lawn mowers.

In general, a starter according to the present invention includes a coilspring which has one end fixed to the starter housing and its other endsecured to a part which may be rotated through a winding mechanism towind up the spring and to store energy therein. A release mechanism isprovided to allow the spring to unwind and supply its stored up energyto a part rotatable with the engine crankshaft for cranking the engine.The connection between the spring and the engine is such that the springand all parts of the starter are completely disengaged from the engineafter the engine has been started.

A principal object of the invention is to provide a new and improvedspring starter for internal combustion engines.

Another object of the invention is to provide a spring starter forinternal combustion engines in which the starting mechanism iscompletely disengaged from the engine after the engine has been started.

Another object of the invention is to provide a starter of the typedescribed which can be wound up manually with a minimum of elfort andthen released by a simple manual operation whenever it is desired tostart the engine.

A further object of the invention is to provide a spring starter of thetype described in which means are provided for preventing the enginefrom transmitting a turning force on thecrank mechanism either duringnormal running of the engine or in the event of an engine backfire.

Other and further objects of the invention will be apparent from thefollowing description and claims and may be understood by reference tothe accompanying drawings, of which there are three sheets, which by wayof illustration show a preferred embodiment of the invention and what Inow consider to be the best mode in which I have contemplated applyingthe principles of my invention. Other embodiments of the invention maybe used without departing from the scope of the present invention as setforth in the appended claims.

- In the drawings: FIG. 1 is a vertical sectional view through a starterconstructed according to the present invention;

FIG. 2 is a to plan view of the starter;

FIG. 3 is a sectional view taken on line 3-3 FIG. 1;

FIG. 4 is a sectional view taken on line 4-4 FIG. 3;

FIG. 5 is a sectional view taken on line 5-5 FIG. 3;

' FIG. 6 is a, sectional view taken on line 6-6 FIG. 1; 7

FIG. 7 is a sectional view taken on line 7---'] FIG. 1;

FIG. 8 is a sectional view taken on line 8-8 FIG. 1;

9 is a fragmentary sectional view similar to FIG. 1 and showing thewinding mechanism in its released position as the spring is unwinding;and

we CC FIG. 10 is a sectional view taken on line 10-10 of FIG. 8.

The starter is shown in FIG. 1 mounted upon the shroud or blower housing10 of a single cylinder internal combustion engine having a crankshaft12 and a flywheel 14 secured on the end of the crankshaft 12. A startercup 16 is secured to the flywheel 14 by a nut 18 threaded onto the outerend of the crankshaft 12. The starter cup 16 extends through an opening20 in the shroud 10 through which air is drawn by the flywheel 14 as isconventional with engines of this type.

The starter includes a base 30 secured to the shroud 10 by screws 32 andhaving suitable openings 34 in its peripheral wall through which air isdrawn by the flywheel 14. The base 30 includes a horizontal wall 36enclosing the starter cup 16. A housing 38 is secured to the top wall 36of the base 30 by screws 40. A coil spring 42 has its inner end 44secured within a slot 46 in a sleeve 48, which is rotatably journaledwithin a collar 50 formed onthe wall 36 of the base 30. The outer end 52of the spring 42 is secured to the housing 38 by a clip 54 having ahooked end 56 receiving the hooked end 52 of the spring. The clip 54 issuitably secured to the housing 38 and has an arm 58 overlying the end52 of the spring to prevent accidental disengagement of the spring fromthe clip 54.

'I'he winding mechanism for winding up the spring 42 includes a pinion60 secured on a shaft 62 which is rotatably journaled in a bushing :64;The lower end of the bushing 64 is supported within an opening in thetop wall 66 of the housing 38. The upper end 68 of the bushing 64extends upwardly through the top wall 70 of a cover 72 which is suitablysecured to the housing 38 with the top wall 70 of the cover spaced fromthe top wall 66 of the housing 38. The pinion 60 is meshed with a gear74 secured on a hub or drive member 76. The hub 76 is provided with apair of flats 78 engaging within a correspondingly shaped hole in thegear 74 so as to be rotatable with the gear. The drive hub 76 isrotatably journaled on a bushing 80 having a collar 82 seated againstthe upper surface 66 of housing 38. The sleeve 48 is freely rotatable onthe drive hub 76.

A hinge member 84 is rotatable on the upper end 68 of the bushing 64 andis secured to the pinion shaft 62 by a screw 86. A crank lever 88 ishingedly connected to the hinge member 84 by rivets 90 and is providedwith a knob 92 at its outer end. The crank lever may be retated manuallyto rotate the gear 74 and drive hub 76 through the pinion 60. The cranklever 88 may be folded over about the hinge pins into the dotted'lineposition shown in FIG. 1.

The lower end of the sleeve 48 is provided interiorly thereof with aseries of longitudinal grooves and the lower end of the drive hub 76 isprovided with a comparable number of downwardly opening slots 102. A key104 is provided with a series of splines 106 engaging within the slots102 in the hub 76. The key 104 is secured on a squared portion 108 of ashaft 110 extending through and slidable axially within the hub 76 andthe bushing 80. The shaft 110 is provided with an enlarged shoulder 112at its lower end for retaining the key 104 thereon. A spring 114surrounds the shaft 110 and reacts between the hub 76 and the key 104 tourge the shaft 110 and the key carried thereby downwardly to theposition shown in FIG. 1 in which the key 104 engages within the slots102 in the hub 76 and also within the grooves 100 in the sleeve 48. Thekey 104 provides a driving connection between the hub 76 and the sleeve48 so that upon rotation of the gear 74 by means of the crank handle 88the sleeve 48 will be rotated with the hub 76 to wind up the spring andstore up en- I ergy therein.

A pawl 120 confined between a pair of washers 122 is rotatable on thelower end of the bushing 64 and is engaged with the teeth of the gear 74as shown in FIG. 7. A spring 124 is secured by rivets 126 to the sidewall of the housing 38 and has its free end 128 engaging the pawl 120 tourge the latter into engagement with the gear 74. The pinion 60 isrotated in a clockwise direction by the crank handle 88, thus rotatingthe gear 74 in a counterclockwise direction. The pawl 120 preventsreverse rotation of the gear 74 and thereby prevents rotation of thedrive hub 76 and the pinion 60 and crank handle 88. except in adirection to wind up the spring. After spring 124 has been wound up inthe manner described, the crank handle may be released and the springwill remain wound because the sleeve 48 is held against rotation by thekey 104, the hub 76 and gear 74 being held by the pawl 120 at such time.

A release lever 130 having a handle 132 is provided for releasing thekey 104 from engagement with the sleeve 48 when it is desired to startthe engine. The release lever 130 is generally circular as shown inFIGS. 2 and 3 and engages the top wall 66 of the housing 38. The releaselever 130 is rotatably journaled on the shaft 110 and is confinedbeneath the head 134 of the shaft 110. The release lever 130 and thetopwall 66 of the housing 38 are provided with complementary cam surfacesfor elevating the shaft 110- and the key 104 upon rotation of therelease lever. The top wall. of the housing 38 is provided with threeinclined grooves or ramps 136 and the lever 130 is provided with threesimilarly shaped ramps 138. The ramps 136 and 138 on the housing andrelease lever are more clearly illustrated in FIGS. 3, 4 and 5, whichshow the release lever in its released or elevated position relative tothe housing 38. The release lever is turned to the position shown insolid lines in FIG. 2 when the spring is to be wound up and the key 104will then be in the position shown in FIG. I- in which it provides adriving connection between the hub 76 and the sleeve 48. When the engineis to be started, the release lever 130 is turned clockwise to theposition shown in FIG. 3 and in dotted lines in FIG. 2. The cammingaction of the ramps 136 and 138 will raise the lever and the shaft 110and key 104 carried thereby to raise the key out of engagement with thegrooves 100 in the sleeve 48, thereby allowing the spring to unwind asthe sleeve 48 rotates about the hub 76.

The sleeve 48 is provided with a series of teeth 140' on its outersurface. The starter cup 16 carries three pawls or blades 142 engageablewith the teeth 140 on the sleeve 48 for cranking the engine when thespring. is released. Each of the blades 142 is provided witha slot 144at its outer end defining a pair of ears146 extending through notches148 in the cup 16. The blades extend inwardly into engagement with theteeth 140 andare pivoted for swinging movement into and out ofengagement with the teeth 140. The blades 142 are urgedinto engagementwith the teeth 140 on the sleeve 48 by springs 150. The spring 150 hasone end 152 engaging the outer surface of the cup 16 and its other end154 extending throughv drive the starter cupv 16 and theengine-crankshaft: in a. clockwise direction through the engagement ofthe teeth- 140'on thesleeve 48 with the blades-142 carried bythestarter. cup. As soon as the engine starts and picks upspeed, thecentrifugal force resulting therefrom-will causethe.inner ends of theblades.-142' to-swing outwardly out of engagement with the teeth andthesleeve 48- 75 and all other parts of the starting mechanism will becompletely disengaged from the starter cup 16 or any other part of theengine while the engine is running. When the engine stops, the springswill return the blades 142 to engagement with the teeth on the sleeve48. As the spring. 42 is being wound up, the sleeve 48 turns in acounterclockwise direction and the teeth 140 will slide past the ends ofthe blades 142 during the winding operation.

A spring has one end 172 secured to the release lever 130 by a tang 174struck from the body of the lever 130 and by means of which the springis clamped to the lever 130. The other end 176 of the spring 170 engagesthe bushing 64. The spring 170 is stressed so that it tends to hold therelease lever 130 in its released position after the spring 42 has beenunwound and the engine started. By reason of this construction thereisno possibility of a drive being transmitted from the sleeve 48 backthrough the hub 76 and the gear reduction to the crank handle 88. Whenthe engine comes to a stop, the blades 142 will engage the sleeve 48and, even though the crankshaft may turn a few degrees in the oppositedirection as the engine finally stops, this driving force imparted tothe sleeve 48 cannot be transmitted back to the crank handle.

When the engine is to be. started, the handle 132 of the release leveris swung in a counterclockwise direction through the slot 180 in cover72 back to the position shown in FIG. 2, which, will drop the shaft 110-and key 104 downwardly until the key engages within the slots. 100 inthe sleeve 48. The gear reduction provided bythe pinion 60 and: gear 74enables the spring 42. to be wound up with very little effort andenables the use of a power spring which is sufficiently strong to insureinstant starting of the engine.

While I have illustrated and describeda preferred embodiment of myinvention, it is understood that this is capable of modification, and Itherefore do not wish tobe limited to the precise details. set forth butdesire to avail myself of such changes and alterations as fall within:the purview of the following claims.

I claim:

1. A starter for an internal combustion. engine, comprising a startercasing, a drive hub rotatably journaled in said casing, means forrotating said hub, a sleeve-rotatable on said hub,- a spiral springhaving one end securedto said sleeve and its other end secured to saidcasing, a shaft slidable axially within saidhub and rotatable therewith,a key on said shaft engageable with said sleevein one axial position ofsaid shaft for rotating said sleeve with said hub to wind up saidspring,a pawl for preventingreverse rotation'of said hub, a release leverrotatableagainst a part of said casing'and engaging said shaft; cammeans on said-release lever and casing oper able upon rotation ofsaidilever for shifting the-same and said shaft axially to disengagesaid key from-said sleeve topermit rotation of said sleeve on said huband' unwinding of thespring, astarter cup secured to the enginecrankshaft, and. a. pawl carried by said-cup and engaging saidsleeve;whereby. unwinding of saidspringwillrotate said cup to crank theengine, said pawl being movable. out ofengagement with-said sleeveinresponseto, centrifugal force upon starting of the engine.

2. A starter for an internal combustion engine,.comprising a startercasing, a gear rotatably journaled'. in said casing, a crank lever andapinion thereon for rotating said gear, a drive hub rotatable with saidgear, a sleeve rotatably mounted in said casing, a spring having'one endsecured to said sleeve and its other end secured to saidcasing, a keyrotatable with said hub and engageable with said sleeve for rotatingsaid sleeve with said hub to. wind up said spring,,a pawl for preventingreverse rotation of'said hub, a release leverrotatable against apartof'said casingandengaging saidfshaft; cam means on said release leverand casing operable upon I rotation:of 'said lever for shifting the sameand said shaft axially to disengage said key from said sleeve to permitunwinding of the spring, a starter cup secured to the engine crankshaft,said sleeve having axially extending teeth on its outer surface andextending into said starter cup, and a pawl carried by said cup andengaging said teeth on said sleeve whereby unwinding of said spring willrotate said cup to crank the engine, said pawl being movable out ofengagement with said sleeve in response to centrifugal force uponstarting of the engine.

3. A starter for an internal combustion engine having a part rotatablewith the crankshaft of the engine, comprising a starter casing, a gearrotatably journaled in said casing, a pinion meshed with said gear, acrank lever for rotating said gear through said pinion, a drive hubrotatable with said gear, a sleeve rotatable on said hub, a spiralspring having one end secured to said sleeve and its other end securedto said casing, a shaft slidable axially within said hub and rotatabletherewith, a key on said shaft engageable with said sleeve in one axialposition of said shaft for rotating said sleeve with said hub to wind upsaid spring, a pawl for preventing reverse rotation of said hub, arelease lever rotatable against a part of said casing and engaging saidshaft, cam means on said release lever and easing operable upon rotationof said lever for shifting the same and said shaft axially to disengagesaid key from said sleeve to permit unwinding of the spring, a startercup secured to the rotatable engine part, said sleeve having axiallyextending teeth on its outer surface and extending into said startercup, and a pawl carried by said cup and engaging said teeth on saidsleeve whereby unwinding of said spring will rotate said cup to crankthe engine, said pawl being movable out of engagement with said sleevein response to centrifugal force upon starting of the engine.

4. A starter for an internal combustion engine, comprising a startercasing, a gear rotatably journaled in said casing, a pinion meshed withsaid gear, a crank lever for rotating said gear through said pinion, adrive hub rotatable with said gear, a sleeve rotatable on said hub, aspiral spring having one end secured to said sleeve and its other endsecured to said casing, a key slidable axially within said hub androtatable therewith, said key engaging with said sleeve in one axialposition thereof for ro tating said sleeve with said hub to Wind up saidspring, a pawl for preventing reverse rotation of said hub, a rotatablerelease lever engaging said key, cam means on said release lever andcasing operable upon rotation of said lever to one position for shiftingthe same and said key axially to disengage said key from said sleeve topermit unwinding of the spring, a part rotatable with the enginecrankshaft, and a pawl carried by said rotatable engine part andengaging said sleeve whereby unwinding of said spring will rotate saidpart to crank the engine, said pawl being movable out of engagement withsaid sleeve in response to centrifugal force upon starting of theengine.

5. A starter according to claim 4 including a spring urging said releaselever toward said one position.

References Cited in the file of this patent UNITED STATES PATENTS1,858,583 Fahrney May 17, 1932 2,042,841 Harmon June 2, 1936 2,386,703McEhnurray Oct. 9, 1945 2,869,682 Millar Jan. 20, 1959 2,875,851 VakosMar. 3, 1959

